Temperature control system



Mardl 1950 F. w. HOTTENROTH TEMPERATURE CONTROL SYSTEM Filed Dec. 11, 1947 INVENTOR.

Patented Mar. 14, 1956 :NITE TIES ATENT QFFEQE TEMPERATURE CONTROL SYSTEM Frederick W. Hottenroth, Goshen, Ind., assignmto Penn Electric Switch (30., Goshen, Ind., a

corporation of Iowa 4 Claims.

This invention relates to a non-electric room temperature control system adaptable for controlling the flow of heat to the room regardless of whether the heat is steam, hot water or hot air.

One object of the invention is to provide a system which is a complete unit connecting a room temperature responsive thermostat with a valve for either steam or hot water or with a damper for hot air as the case may be.

Another object is to provide a main control valve which is actuated by the heat of the heating medium and is controlled by a pilot valve which in turn is operated by a temperature responsive element, the pilot valve being connected by means of capillary tubes or the like with the main valve to form therewith a closed pressure operated control system.

Still another object is to provide a pilot valve associated with a pair of chambers and the chambers being connected with a pressure chamber of the main valve in such manner that the main valve when heated will vaporize a portion of a liquid therein thus displacing the liquid into one chamber of the pilot valve, the pilot valve being closed. When the pilot valve opens it permits the liquid to flow into the other chamber thereof and return to the pressure chamber of the main valve for i e-vaporization of the liquid to produoe an operating pressure which eiiects closure of the main valve.

A further object is to design the main valve so that a snap-acting efiect is had on both opening and closing.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my control system whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, wherein:

Figure l is a diagrammatic view of my individual room temperature control system showing the parts in dormant position with no heat .flow through the main valve, the thermostat being in the cold position.

Figure 2 is a similar view showing heat flow and the main valve open.

Figure 3 is a similar View showing the thermostat satisfied and commencing to close the main valve, and

Figure 4 is a similar view showing the main valve closed.

On the accompanying drawing, I have used,

the reference numeral Ill to indicate a spring opened main valve with a pipe 62 for steam or the like leading thereto and a pipe l4 leading therefrom as to the radiator or other room heating unit. The spring for the valve it is shown at l 9.

In the following specification, I will refer to steam as the heating medium although the described system is operable in conjunction with a hot water valve or a hot air damper, and it is to be understood that the claims are to be construed broadly enough to encompass either a damper or a valve when reference is made therein to the main valve.

The heating medium or main valve Ill has as sociated therewith a pressure chamber l6 and a sealing bellows it for sealing the pressure chamber off from the outgoing side of the valve I 0 yet allow steam pressure to act inside the bellows.

A room temperature responsive element in the form of a bimetal strip 2!} is illustrated anchored at 22. Its opposite end is adapted to operate a spring closed pilot valve 2 which closes and opens communication between a pair of chambers 26 and 28. The spring is shown at 25. The

chamber 26 is connected by a capillary tube 30 with the lower portion of the chamber l6, and a capillary tube 32 connects the chamber 28 with the upper portion of the chamber It. A sealing bellows 34 is provided to seal 01f the chamber 26 from atmosphere.

A range spring 36 is provided for the bimetal element 20 and the thermostat may be adjusted by means of a screw 38 to raise or lower the range as desired.

Practical operation In the operation of my individual room temperature control system, asuming the parts in the dormant position of Figure 1 with no steam flow and the thermostat cold, the valve ill will be open and the valve 2 will be closed. Within the chamber It is a small quantity of liquid capable of vaporization when steam is admitted to the pipe l2.

When steam is admitted, the pipes 12 and I4 and the housing for the chamber it become heated thus vaporizing some of the liquid Mi (indicated by the reference numeral M19) and displacing the rest of it through the capillary tube 30 into the upper chamber 26 of the pilot valve 24 as illustrated at 45a in Figure 2. Drops of liquid are shown issuing from the tube 38 into the chamber 26.

The action just described permits the valve Ill to remain open as the liquid is then out of the chamber l and most of it is in the colder chamber 25 exposed to room temperature. This of course is desirable because the thermostat is still cold and we therefore want steam flow as illustrated.

When the room thermostat becomes satisfied, the bimetal element 20 will Warp to the hot position of Figure 3 which permits the liquid 46 in the chamber 23 to flow back through the tube 32 and into the chamber l6. Drops of liquid ltc are illustrated to show this action. The liquid is vaporized in the chamber l6 thus filling the entire closed system i i-4 5-2830--32 with vapor i612 as illustrated in Figure 4 andcreating a pressure therein that closes the main valve Hlagainst further steam flow.

The steam reaches the valve is howeverand keeps it hot thus keeping the liquid at in the vapor stage ltlb in Figure 4 to maintain the valve closed until such time as the room thermostat again ..,calls for heat and closesthe pilot valve 24 as in .Figure 2. The cycle of operationsis then repeated beginning with condensation of the vapor 551) into liquid 43a in the chamber 26 until such time as the room thermostat is again satisfied. Such condensation of course will permit-the main valve to open.

If for any reason the steam is turned off to the pipe i2 while the room thermostat is satisfied, the vapor 55b will condense back to liquidand when steam reaches the main valve is againit will ,revaporize the liquid creating a build-up of pressure to again close the valve unless the room thermostat is thencalling for heat.

Assuming the parts in the position of Figure 3, vapor pressure is being built up in the closed system and is compressing the bellows 18. As soon as the main valve it) starts to close pressure will reduce in the pipe i4- and likewise inside the bellows it, which reductionof pressure together with increase of pressure to the vapor in the chamber it will accelerate the closing of the main valve is thus eifecting substantially snap action thereof. Thissnap action occurs because the effective area of the seatof the valve Iii is smaller than the effective area of the bellows I8. Likewise upon opening, as soon as the valve cracks vopen, sli ht pressure builds up in the pipe i l and inside the bellows is to give snap action.

From the foregoing specification,it will be obvious that I have provided a control system which is simpleas far as'structure .isconcerned and is not at all complicated from the standpoint of installationwhich requires noelectrical wiring but merely capillary tube connections between the pilot valve and the main valve.

Some changes may be made in'the construction and arrangement of the parts of my system without departing from the real spirit and purpose of my invention, and it is my intention to cover by any claims any modifiedforms of structure or use 'ofinechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

1. In an individual room temperaturecontrol system, a normally open main valve for a heating medium, a pressure chamberfor closing said main valve upon build up of pressure therein, a pilot valve, a pair of chambers between which said pilot valve efiects control of the flow of fluid, one

of said chambers beingabove-the other, a capillary tube connection between the lower portion of said pressure chamber and the upper of said chambers, a second capillary tube connection betweenthe upper portionof-saidpressure; chamber and the lower of said chambers, said pressure chamber, one of said capillary tub-es said upper and lower chambers and the other of said capillary tubes in series constituting a closed fluid and vapor system, a small quantity or" fluid in said system and a temperature responsive element for operating said pilot valve to open the same when the temperature rises and close it when the temperature falls, said pressure chamber being subject to the temperature or the heating medium flowing to said main valve.

2. In an individual room temperature control system, a main valve for a heating medium, a presvsure chamber having vaporizable fluid therein for operating said main valve, a pilot valve, a pair of chambers between which said pilot valve effects control of the flow of such fluid, a hydraulic connection between the lower portion of said pressure chamber and the upper of said pair of chambers, a hydraulic connection between the upper portion of said pressure chamber and the lower ofsaid pair of chambers, and room temperature responsive ,means for operating said pilot valve, said pressure chamber being subject to the temperature of the heating medium flowing to said main valve for effecting vaporization of said fluid.

3. In a temperature control system of the class described, a main valve for a heating medium, a pressure chamber, a pilot valve, upper and lower chambers between which said pilot valveefiects control of the flow of fluid, tubeconnections between the bottom of said pressure chamber and the upper pilot valve chamber and between the top of said pressure chamber and the lower of said pilot valve chambers, temperature responsive means for operating said pilotvalve to open the same when the temperature rises and close it when the temperature falls, saidpressure chamher having fluid therein subject to the temperature of the heating medium fiowingto said main valve, said main valve having a bellows ioroperating the same, said bellows being subject to the the lower of said chambers of said housing,.tem-

perature responsivemeans for operating said-pilot valve, and a bellows for operating said main valve, said bellows constituting one wall of said pressure chamber.

FREDERICK W. HOTTENROTH.

REFERENCES QITED The following referencesare .of record in the file of this patent:

U NLTED STATES PATENTS Number Name "Date 1,129,433 Stratton Feb. 23,1915 1,285,991 Halsey NOV.'26, 1918 1,744,632 Halsey J an.2l, 1930 1,867,384 Scherbius 'Julyl2,'l932 2,286,296

McGrath 'June'16, 1942 

